code: def _downgrade_v2(op):
      """
      Downgrade assets db by removing the 'auto_close_date' column.
      """
      # Drop indices before batch
      # This is to prevent index collision when creating the temp table
      op.drop_index("ix_equities_fuzzy_symbol")
      op.drop_index("ix_equities_company_symbol")
  
      # Execute batch op to allow column modification in SQLite
      with op.batch_alter_table("equities") as batch_op:
          batch_op.drop_column("auto_close_date")
  
      # Recreate indices after batch
      op.create_index(
          "ix_equities_fuzzy_symbol",
          table_name="equities",
          columns=["fuzzy_symbol"],
      )
      op.create_index(
          "ix_equities_company_symbol",
          table_name="equities",
          columns=["company_symbol"],
      )
  
file_path: catalyst/catalyst/assets/asset_db_migrations.py
imports: from functools import wraps
  from alembic.migration import MigrationContext
  from alembic.operations import Operations
  import sqlalchemy
  from toolz.curried import do, operator
  from catalyst.assets.asset_writer import write_version_info
  from catalyst.errors import AssetDBImpossibleDowngrade
  from catalyst.utils.preprocess import preprocess
  from catalyst.utils.sqlite_utils import coerce_string_to_eng
label_desc: Use image node_id 5 for calling a global function with example usage: _downgrade_v2(op) without return types